GCRI · Space and Earth Observation
Communications and navigation
Satellite communications connect remote areas, ships, aircraft and disaster zones, and navigation satellites provide the position and timing that transport, telecom, finance and power grids depend on. Large new constellations are changing both. This page sets out how satellite communication and navigation services work, how society’s dependence on them can be mapped, and what evidence serves the regulators and operators who plan for their loss.
Communications and navigation on the record.
Communications and navigation: how the risk develops.
GNSS, satcom and dependency. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Constellations change connectivity
Large low Earth orbit constellations offer lower latency broadband, extending coverage but concentrating it with a few operators.
Timing is a hidden dependency
Telecom networks, power grid measurement and financial systems use satellite time signals. Many users do not know they depend on them.
Navigation underpins transport
Aviation, shipping, road logistics and agriculture rely on satellite positioning, with augmentation systems for higher accuracy and integrity.
Backups are often missing
Alternative positioning and timing, such as terrestrial systems or holdover clocks, are unevenly deployed, so outages can cascade.
How communications and navigation is modelled, measured and tested.
The model, its assumptions, its data and its uncertainty, in the form a scientist or engineer would check. Structures follow published methods. The values drawn are illustrative, not findings.
Earth observation chain
How a satellite or sensor record becomes evidence on communications and navigation, and where each step adds uncertainty.
- 01 · Acquireorbit, sensor and revisitUncertainty: gaps from cloud and orbit
- 02 · Calibrateradiometric and geometricUncertainty: sensor drift
- 03 · Correctatmosphere and terrainUncertainty: aerosol and slope assumptions
- 04 · Retrieve or classifythe variable or the classUncertainty: model and training error
- 05 · Validateagainst ground truthUncertainty: sample design and size
- 06 · Publishwith error bars and lineageUncertainty: stated, never hidden
Satellite communication and navigation reach every domain.
Findings are designed for the Strategic Systems series. Spectrum is governed by the ITU Radio Regulations; the Global Centre for Risk and Innovation (GCRI) recommends no provider.
- Interference and outage records.
- Connectivity studies in remote areas.
What is measured, and how well.
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Population covered by satellite broadband | percent of population | annual | Regulator and operator data | ESTIMATED |
| Critical sectors using GNSS timing | count of sectors | per assessment | Dependency studies | ESTIMATED |
| Timing holdover capability | hours | per system | Operator documentation | DECLARED |
| Satellite broadband subscribers | count | annual | Regulator statistics | Published statistics |
| Satellite-based augmentation coverage | status by region | per assessment | Augmentation system documentation | Published statistics |
| Navigation outages and degradations | count and duration | annual | Service notices | Published statistics |
Where the evidence comes from.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| ITU satellite network filings and Radio Regulations | Spectrum and orbit filings | Public, ITU terms |
| GNSS service performance reports (GPS, Galileo, GLONASS, BeiDou) | Service performance and notices | Public, terms per provider |
| Government studies of GNSS dependence, such as the UK and US economic impact studies | Sectors depending on positioning and timing | Public records, licence per government |
| National telecom regulator statistics | Satellite broadband adoption | Public records, licence per regulator |
| ICAO and IMO documentation on navigation | Navigation requirements in aviation and shipping | Public, terms per organisation |
Who decides, and what the evidence serves.
Space and Earth Observation prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Telecom and transport regulators | What backup timing and navigation to require | Dependency maps; backup reviews |
| Critical infrastructure operators | How long they can operate without satellite timing | Holdover evidence |
| Governments planning connectivity | Where satellite broadband fills gaps | Connectivity gap analyses |
Outputs this topic produces
- Dependency maps of positioning and timing
- Backup capability reviews
- Connectivity gap analyses including satellite options
- Evidence notes for resilience planning
What experts ask.
Specialists in navigation and satellite communications ask how dependent systems are and how they fail.
- Which sectors rely on satellite timing and positioning, and do they know it?
- How vulnerable are receivers to jamming, spoofing and interference?
- What alternative time and position sources exist, and are they in use?
- How do satellite communications support emergency response and remote areas, and how resilient are they?
- How does the growth of large communications constellations change dependency and risk?
Weak signals, wide dependence.
Navigation satellites broadcast signals that receivers use to calculate position and time. The signals are very weak by the time they reach the ground, which makes them easy to drown out with jamming or imitate with spoofing. Beyond navigation for transport and agriculture, the timing function is embedded in telecommunications networks, electricity grid synchronisation and the time-stamping of financial transactions, often without operators being aware of it.
Satellite communications carry data, voice and broadband to ships, aircraft, remote communities and disaster zones where terrestrial networks are absent or damaged. They are themselves exposed to interference, ground-segment faults and space weather. Resilience comes from diversity: multiple constellations, terrestrial backups, holdover clocks that maintain time during outages, and receivers that detect anomalies.
How the evidence is built, and where it stops.
- 01
Dependency surveys
Identifying where timing and positioning are used in critical services. Embedded dependencies are often undocumented.
- 02
Interference monitoring
Detecting jamming and spoofing through receiver networks and communications and network technology. Coverage of monitoring is limited.
- 03
Resilience testing
Testing how systems behave when signals are lost or falsified. Live testing is constrained by regulation and safety.
- 04
Signal and orbit physics
Modelling signal propagation and errors, grounded in physics. Atmospheric effects vary in ways that are hard to predict locally.
How it is studied, and what the methods cannot say.
- 01Communications and network technologyData distribution to users · Spectrum protection for EO · Ground station networksApplied here
- 02Space systems and satellite servicesMission continuity analysis · Space segment resilience · Debris compliance assessmentApplied here
- 03Geospatial information systemsIntegrating EO with administrative data · Catalogues and interoperabilityApplied here
- 04Physics and quantum scienceRadiative transfer for atmospheric correction · Microwave scattering · Orbit determinationApplied here
Where this page’s references lead.
The bodies and documents this page is read against. Status and editions change; each link goes to the issuing body.
Questions and answers.
What is GNSS?
Why do power grids and banks depend on satellites?
What is a low Earth orbit constellation?
Why does finance depend on satellite navigation?
What is spoofing?
Are there alternatives to satellite timing?
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